Pilot structure



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Patented Apr. 17, 1951 PILOT STRUCTURE Harold B. Donley, Columbus, Ohio, assignor to Columbus Metal Products, Inc.,

Columbus,

Ohio, a corporation of Ohio Application April 8, 1948, Serial No. 19,718

(Cl. S- 91) 9 Claims. 1

My invention relates to an improvement in pilot structures for vaporizing pot type burners. One purpose is to provide a pilot structure with a minimum turn-down.

Another purpose is to provide a pilot structure which is simple and eflicient.

Another purpose is to provide a pilot structure which may be readily applied to a burner pot.

Another purpose is to provide an improved means for holding a pilot structure firmly in position within the pot.

Another purpose is to provide improved air admission means for a pilot structure.

Another purpose is to provide improved combined securing and air admission means for a pilot structure.

Other purposes will appear from time to time in the course of the specification.

I illustrate my invention more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a vertical axial section;

Figure 2 is a section on the line 2-2 of Figure l; and

Figure 3 is a section on the line 3-3 of Figure 1.

Like parts are indicated by like symbols throughout the specication and drawings.

Referring to the drawings, I generally indicates an outer housing or drum. It may be of any suitable form, but for convenience I prefer to make it cylindrical, and to have associated with it an upward continuation 2 which may serve as a combustion chamber or radiating member. It will be understood that any suitable flue connection, not herein shown, may be provided for it. The bottom of the housing I is shown as closed by a bottom wall 3 which has a central aperture 4. Any suitable supporting means may be employed for spacing the housing upwardly from the ground, orffrom the supporting surface, to permit air to flow inwardly below the partition 3 and upwardlyv through the aperture 4. 5 generally indicates an angle ring, welded or otherwise secured to the housing 2. 6 generally indicates a vaporizing burner pot, shown as including a circumferential side wall Al, an upwardly concave bottom or end wall 8, and an outwardly extending top flange 9 which rests upon the angle ring 5.

I0 is any suitable flame ring, centrally apertured as at II, which partially closes the top of the pot 6. The pot is provided with a plurality of primary air inlets I2 shown as arranged in a plurality of rows which extend circumferentially around the side wall of the pot. I3 indicates any suitable secondary air inlet means. I illustrate, for example, a single row of upwardly tilted secondary inlets which are both larger and more closely spaced than the primary inlets i2. I4 is a liquid fuel supply pipe or duct adapted to admit liquid fuel to the vbottom 8 of the pot 6, for vaporization.

Any suitable means, not herein shown, may be employed for varying the rate of ow of liquid fuel along the pipe I4 to the pot. I may, for example, employ a conventional and Well known float valve assembly, the details of which do not, of themselves, form part of the present invention, or I may employ any suitable manual control, diagrammatically illustrated as at I5 in Figure 1. It will be understood that when the burner is burning at high fire, liquid fuel is vaporized on the pot bottom and rises upwardly through the pot. It receives and is mixed with the primary air entering through the inlets I2. This air is insuflicient in volume, in relation to the volume of vaporized fuel, to form a final and completely combustible mixture. However, the primary mixture, when it continues rising toward the top of the pot, receives from the 'secondary air inlets I3 suflicient secondary air to complete a fully combustible mixture which burns at or above the level'of the inlets I3. In normal use of the device a substantial flame will extend from and above the top of the pot.

In this type of burner the provision of pilot or low float turn-down means is important. For example, it may be desirable to maintain a minimum re without any substantial or perceptible heating effect. I illustrate a pilot structure which has substantial advantages. It includes unitary securing and rair 'supply means which may be used in connection with a wide variety of pilotpiece design. It will be understood,.therefore, that the particular pilot structure herein shownmay be widely Varied.

Referring, however, to the pilot piece :as shown, I illustrate a generally circumferential side wall 20 which has outwardly extending ears 2| which, with the inward continuations 22 of the side wall 20, define separate spaces. The space within or surrounded by the pilot wall 2D is partially closed by an inwardly extending intermediate wall 23 which terminates in an upwardly extending inner and, preferably, cylindrical wall 24. The space between the top of the wall 24 and the top of the wall 20 is vclosed by a top Vvaried, tov suit particular conditions.

wall 25, all as shown in Figures 2 and 3. It will be noted that the top wall 25 lies at a level below the lowest of the primary air inlets l2, and that, therefore, no air is admitted to the interior of the pilot structure from or through the pot side wall. I may, in fact, find it advantageous to provide anoilset portion of the wall 20; as at 2E, which actually abuts against the inner surface of the pot side wall 1, and which is connected -to the side wall 2i] by connecting Vportions 21. The wall 26 is apertured or cut away, as at 28, in line with the liquid fuel inlet duct I4, to the end that liquid fuel will ow upon the bottom of the pot for Vaporization.

In order to hold the pilot structure in position,

and, at the same time, to supply air for pilotv combustion, I provide upwardly entending tubular airthrough thentubes 30, and, at the same time, yto hold the pilot'piece in position, `I illustrate Y `inwardlyscrew-threaded caps 33 which are screwth'readed atthe tops of the tubes. 3e indicates suitable washers or packings. It will be understood, of course, that-any other suitable f topsecurihgm'e'ans may be employed, but the structures illustratediin Figure 3'does provide unitary n'ieansrfor' at the same time holding the pilot structure firmly' inposition, and for supplying air t` its interiori.' It will be understood that thetop'w'a'll 25', where itoverlies the space surrounded by the side' wall offsetsZl, may have a suitably' formed or enlarged aperture 35 through Vwhicli'the upper end of the tube 3Q passes.

' It will be noted that the wall 23 may be provided' with a' plurality of downwardly directing air openings 36, while the wall'25 may be provided with a-"plura'lity of upwardly and inwardly directing airy openings-37'. It willbe understood that the arrangement of a'irV outlets may be widely The pilot piece' may, ifdesired, have one'or more side openings 38, In Figurev l, I' illustrate a single such opening through which unvaporized liquid fuel mayA flow' outwardly upon the bottom of the pot,

whenthe burner is atV high re.

It will be ,realized that, whereas, I have described and illustrated a practicaliand operative device, neverthelessmany changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention.V I thereforeV wish mydescription and drawings to be taken as in a broad sense illustrative or diagrammaticgrather than as Ylimiting me to my Iprecise showing.

4 possibility of substantial leakage. Preferably, the end of the duct I4 extends through an appropriately formed aperture 21, or isproperly aligned with the aperture 2l, so that liquid fuel flows freely into the interior of the pilot piece. It will be understood, however, that, if desired, the wall 26 may be omitted. The relatively large size of the apertures 35 permits the pilot structure to be adjusted against a side wall l of the pot, and to be firmly locked, by the screw-threaded caps 33, in the adjusted position. As is clear from Figures 2 and'3, I illustrate the large aperture 35 in connection with only one of the tubes 30. If necessary, both apertures may be enlarged.

It will be understood that whereas I have shown astructure in which two hollow connectors are employed, it is, under some circumstances, practical to use but a single connector. It will be understood, also, that the size, shape and proportion of the pilot piece itself may be widely varied. For example, I donot wish my invention to be limited to use with a pilot piece in which an upward opening is employed.

. Iclaim:

1; For use as a pilot structure for lpot type burners a pilot piece having a side wall and a top wall defining an interior space, means forY holding the pilot pieceirmly in predetermined position within and downwardly against the botto'm of a pot burner, said means including a hollow connector member, and means for securing the hollow connector member to the bottom of a pot burner with the interior of said hollow connector member in communication with air below the pot burner, and means mountable on said hollow connector member and engageable with said pilot piece and adapted, when so engaged, to direct a substantial downward thrust upon said pilot piece towards the bottom of a pot burner, when mounted therein, said hollow connector member having a laterally directed air passage adapted for communication with the interior of the pilot piece, when the pilot piece and hollow connector member are operatively assembled.

2. The structure of claim l, characterized by and including two hollow connector members located one at each side of the pilot piece.

3. The structure of claim 1, characterized by said unitary pilot piece having walls defining a plenum chamber a-nd a mixing chamber, said laterally directed :air passage of the hollow con-V n ector being in communication with the interior of said plenum chamber when theY pilot p-iece and hollow connector are operatively assembled.

4. The structure of claim 1, characterized byY and including a hollow connector extending upwardly above the top of the pilot piece, and a connector member on said connector formed and adapted to engage the top of thepilot Ypiece and tourge the pilot piece downwardly toward the bottom of the burner.

5. 'If-he structure of claim l, characterized by and including a pair of hollow connectors extending upwardly above the top of the pilot piece, and connector members on said connectors formed and adapted to engage the topof the pilot piece and to urge the pilot piece downwardly toward the burner, said pilot piece being apertured and said hollow connectors passingv through said apertures, the hollow connectors and-said apertures being dimensioned to permit a range of lateral play between the connectors and the pilot piece,

tion to the connectors prior to tightening the securing members.

6. In combination with a burner pot having a bottom wall provided with an aperture, and a side wall having a liquid fuel supply duct extending therethrough, a pilot piecehaving walls defining an interior space, and means for holding the pilot piece firmly downwardly against the bottom of the pot, said means including an open ended hollow connector member provided with a laterally directed aperture, the lower end of said hollow connector member being secured to the bottom of the pot, said hollow connector member extending upwardly therefrom with its interior in communication with the air outside of the pot through said aperture in the bottom of the pot and in communication with the interior .n

of the pilot piece through` said laterally directed aperture in the connector member, and means on the upper end of the hollow connector member closing said end and engaging the pilot piece for directing a substantial downward thrust thereon against the bottom of the pot, the pilot piece having an otherwise open bottom adapted to be closed by the bottom of the pot, said pilot piece Y being positioned within the pot interiorly to receive liquid fuel delivered to the interior of the pot by said liquid fuel duct.

7. The structure of claim 6, characterized by said pilot piece having a mixing chamber in its Vbottom portion and a plenum chamber in its upper portion, said plenum chamber having an inner wall portion defining and surrounding a flamevoutlet extending upwardly from the mixing chamber.

8. 'I'he structure of claim 6, characterized by `said pilot piece having a mixing chamber in its bottom portion and a plenum chamber in. its upper portion, said plenum chamber having an inner wall portion dening and surrounding a ame outlet extending upwardly from the mixing chamber, said connector member having the laterally directed outlet positioned intermediate its ends and in communication with said plenum chamber.

9. The structure of claim 6, characterized by said pilot piece having a mixing chamber in its bottom portion and a plenum chamber in its upper portion, said plenum chamber having an inner wall portion dening and surrounding a. llame outlet extending upwardly from the mixing chamber, said connector member having the laterally directed outlet positioned intermediate its ends and in communication with said plenum chamber, and having an upper end portion extending upwardly above the pilot piece and a locking member thereon adapted to engage an upper surface `of said pilot piece.

HAROLD B. DONLEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Livar et al. Jan. 15, 1946 

